Studies on Deterioration Process of Dental Materials

利用三体磨损试验机研究填料类型和填料含量对树脂复合材料耐磨性的影响。采用无机填料、树脂单体（Bis-GMA/TEGDMA）、光引发剂、促进剂和抑制剂制备了实验性光固化树脂复合材料。无机相采用五种填料（石英，Q；无定形二氧化硅，Am；钡玻璃，Ba；锶玻璃，Sr；微细二氧化硅，MF）。对于每一种树脂复合材料，填料的粒径分布都尽量相同。填料的平均尺寸约为3.0 i m。此外，另外两种复合材料分别填充了20wt%和40wt%的微细二氧化硅填料。体外磨损试验采用Alabama磨损模拟器进行。磨损测试后，使用3d激光扫描仪测量磨损量。结果表明，Am、Ba、Sr和Q在填料含量分别为40%、60%和70%时磨损损失最大。Am-和ba -复合材料在不同填料含量的复合材料中表现出显著差异，而Q-和Sr-复合材料则无显著差异。其次，当基体树脂中填充量超过60%时，am负载的复合材料表现出最大的耐磨性，其次是Ba和q负载的复合材料。无论填料含量如何，含锶的复合材料均表现出最大的穗量。在填料载荷小于40%的情况下，微填充材料在两种情况下的磨损量都显著减少。添加20 wt%的微填料到60 wt%的常规树脂复合材料（杂交）增加了所有填料类型的抗穗性。通过填料体系的杂化，达到与微填充复合材料相同的磨损水平。结果表明，填料的尺寸、种类和含量对树脂复合材料的耐磨性有一定的影响。

The purpose of this study is to investigate the effects of filler type and filler content on the wear resistance of resin composites using a three-body wear testing machine. Experimental light-cured resin composites were fabricated with inorganic fillers, resin monomers (Bis-GMA/TEGDMA), photo-initiator, accelerator and inhibitor. Five kinds of fillers (Quartz, Q; Amorphous silica, Am; Barium glass, Ba; Strontium glass, Sr; Microfine silica, MF) were used as inorganic phase. For every resin composites, the filler size distribution was tried to be the same as much a possible. Mean filler size was around 3.0 i m. In addition, two additional composites were filled with 20wt% and 40wt% microfine silica fillers. The in vitro wear testing was carried out using the Alabama wear simulator. After wear testing, the amount of wear was measured with 3D-laserscanner. As a result, Am, Ba or Sr and Q showed the maximum wear loss when the filler content was 40, 60 and 70 wt %, respectively. Am- and Ba-loaded composites showed a significant difference among the composites with different filler content, while no difference was found with Q- and Sr- loaded ones. Next, when more than 60 wt% of fillers are loaded in matrix resin, Am-loaded composites showed the most wear resistance, then followed by Ba- and Q-loaded ones. Sr-containing composites exhibited the largest amount of ear irrespective of filler content. At a filler load less than 40 wt% the microfilled materials had in both cases a significantly reduced amount of wear. Addition of 20 wt% microfillers to 60 wt% conventional resin composites (hybridization) increased the ear resistance for all filler types. The same level of wear as with microfilled composites is reached by hybridization of the filler system. It could be concluded from these results that size, type and content of fillers influence the wear resistance of resin composites.